Satō Shori Pulls Double Duty as Star and Singer
timelesz member Satō Shori (佐藤勝利) isn't just lending his voice to anime film Kimi to Hanabi to Yakusoku to — his group wrote the theme song for it, too. The track, titled "Kienai Hanabi" (消えない花火, roughly "Fireworks That Never Fade"), was announced by Anime Anime as the film's official theme.
It's Satō's first anime film lead, and the dual role clearly means something to him. "Fireworks may be a momentary flash of light," he said in a statement. "But they also leave something that stays deep in your heart forever. I hope we've captured that in the theme song."
The film is produced at SynergySP and Answer Studio — SynergySP is a subsidiary of Shin-Ei Animation, the studio behind Doraemon and Crayon Shin-chan, which also co-distributes the film alongside Shochiku.
A Cast That Bridges Anime and Live Action
The film assembles an unusual lineup that spans voice acting, live-action film, and comedy. Hara Nanoka (原菜乃華), who broke out internationally as Suzume Iwato in Makoto Shinkai's Suzume, plays heroine Hayama 煌 (likely read Hikari or Kira — official furigana hasn't been confirmed).
Takahashi Rie (高橋李依), known to Western anime fans as Emilia in Re:Zero and Megumin in KonoSuba, voices Haru, a mysterious girl who appears to have wandered in from the past. Takahashi noted that the Nagaoka dialect was a first for her: "I started by learning from the guide audio in the recording footage, and on the day of recording, people from Nagaoka watched over us as we worked through it."
Rounding out the main cast is comedian Yokozawa Natsuko (横澤夏子) as Makoto's mother, Natsume Yukari. A Niigata native herself, Yokozawa called it "an honor to be part of a wonderful work connected to my home prefecture."
A Fireworks Love Story 81 Years in the Making
The film adapts Mado Kaoru's novel of the same name, published under Shogakukan's Gagaga Bunko imprint. The story follows Natsume Makoto, a high-school student who on his first day is approached by classmate Hayama 煌 with the words "I've always wanted to meet you." Chasing the mystery behind a single fireworks painting, Makoto travels to Nagaoka and encounters Haru — setting off a narrative that spans 81 years and unravels a promise exchanged across time.
The setting is Nagaoka's Grand Fireworks Festival, one of Japan's three great fireworks displays, which draws hundreds of thousands of visitors to Niigata every year. The film has the backing of Niigata Prefecture, Nagaoka City, and the Nagaoka Fireworks Foundation.
鈴木慧 (likely Suzuki Kei) directs, with a screenplay by Mori Kōhei (森こうへい).
Looking Ahead
Kimi to Hanabi to Yakusoku to opens nationwide in Japan on July 17, 2026. No international distribution or streaming partner has been announced yet. The official trailer was previously available on YouTube via Shin-Ei Animation's channel but is currently set to private — expect a public re-upload as the release approaches.
The source novel is published by Shogakukan's Gagaga Bunko label; no English-language release has been announced. With Shochiku handling theatrical distribution in Japan, international anime fans will want to watch for a pickup by Crunchyroll, GKIDS, or another Western distributor as the premiere date nears.